Power tube



w. E. KUHLE 4 HERNE POWER TUBE AFiled March 4, 1931 IINVENTOR WILHELM fummo K me BY VFL/g n ATTQRNEY Patented Feb. 18, 1936 y UNITED STATES PATENT OFFICE POWER TUBE Wilhelm Eberhard Khle, Berlin, Germany, assignor to Telefunken Gesellschaft fr Drahtlose Telegraphie m. b. H., Berlin, Germany, a corporation of Germany Application March 4, 1931, Serial No. 520,061 In Germany March 7, 1930 1 Claim. (Cl. 'Z50-27.5)

This invention relates to an arrangement for space formed by the anode walls. The protective the protection of heated metal bodies in iloW- wall coatings are indicated by 4 and 5, these wall Contact with flowing water. coatings 4 and 5 are attached to the walls I and The present invention is concerned with ways 2 by any suitable means. I prefer a metal for 5 and means adapted to preclude incrustations or the surface of the body to be protected which 5 boiler scale on the surface of heated metal parts metal or material exhibits but low chemical afin contact with flowing water, especially the elec'- nity to oxygen, for instance, tin or a metal postrodes of electron discharge tubes of large power. sessing still more marked electronegative charac- This formation of scale or incrustations is parteristics. Tin is particularly suitable, a coat of 10 ticularly noticeable in such electrodes as the tin is technically very easily fastened upon base 10 anodes. metals such as iron and copper.

It has been found that such incrustation will I claim: happen only when a reaction takes place simul- An electron discharge power tube having electaneously between the surface of the metal and trodes, at least one of said electrodes having 15 oxygen. According to the present invention as hollow double iron walls, and. a liquid cooling 15 illustrated in the accompanying drawing, which means within said hollow walls having a coating is a vertical cross section of the hollow anode of tin to protect the iron walls from the formaplorton of a fluid cooled vacuum tube. The holtion of ncrustations where said hollow walls are low anode walls l and 2, which may be either or in contact with the cooling liquid. 20 both anode or cathode electrodes, are cooled by 20 a ow of cooling fluid 3 circulating within the WILHELM EBERHARD KHLE- 

